I hope I'm posting to the right place, and I know that I get to keep the pieces...

That being said, I'm starting to do some music production on my notebook, and I'm wondering whether it would be necessary/advisable to use a non-slh, i.e. realtime/low-latency kernel, for it. Is this even necessary nowadays?

I'm trying to create some simple backing tracks for guitar practice and ambience "soundtracks" for game modding. I'm using JACK and stuff like QSynth, Hydrogen, Rosegarden, and I'm on a Sony Vaio VGN-FZ11S notebook.

The latest RT kernel is still 2.6.33 version, isn't it?
and I heard (just heard, not tried) that newer version of kernel has already very low latency
that you don't feel the difference...
so.. I'd first suggest try your music setting on current kernel of aptosid, without extra
burden of other processes. (i.e. not starting many deamons and applications in parallel.)

Only when you have latency problem in real, you may consider switching to RT kernel.

makke and holo used to provide RT patched version of slh kernels, but I don't know if they
continue...

Personally I have compliled my own kernel 2.6.33, that is the last version of realtime kernel. A new version was announced for kernel 2.6.37 but now we are at 2.6.38 and nothing is out.
It is true that the last kernels are a lot better for realtime. For example you can use some video player or music player with jack without problems. However, if you need something more a non-realtime kernel is not enough. At 192 khz and 24 bit, for example, and some midi files with linuxsampler and Bosendorfer 290 samples only real time kernel can achieve a useful performance. The same if you are recording multitrack with ardour.

Stay away from pengutronix, since it seems there are some incompatibility with aptosid configuration. If you need an howto for compiling the kernel, let me know.

I'm starting to do some music production on my notebook, and I'm wondering whether it would be necessary/advisable to use a non-slh, i.e. realtime/low-latency kernel, for it. Is this even necessary nowadays?

I'm no kernel expert at all, but like others say, I don't think it's really necessary any more like it once was. I use Ardour on an RME HDSP 26-channel card (albeit at 48kHz) running slh kernels and experience no xruns with <3ms JACK latency, which is good enough for me. There was a bad phase many months ago when Ardour's GUI would pause for a while (but audio usually continued unaffected), but I suspect Intel graphics issues (or my olde hardware) caused that, and it no longer happens since somewhere in late 2.6.36 or early 2.6.37 vintage.

Last year I had similar questions, and read this on that very page at Debian Multimedia which confirmed my thoughts:

Debian Multimedia wrote:

Realtime kernel

The Debian Multimedia team is not working on including a kernel image with the realtime-patches applied in Debian. Much of the realtime-patches have been accepted in the mainline kernel, to the point that for most purposes the stock Debian kernel is suitable even for realtime-like work.

If you'd like to use a kernel with the realtime-patches applied anyway, you might want to consider adding the pengutronix repository

I'd like to take this opportunity to thank slh and all the aptosid devs who make Debian sid so usable. I used to use 64Studio but switched when I found sidux, as Linux Audio is one field where you need recent packages.

That page is hindered by no date or hints at age, not to mention even less web design then my Home Page. It references a thread from the great Dave Phillips from back in 2000, and may not have been changed since 2007:

I don't know, but I am writing this inside 2.6.33 kernel realtime now. No errors at boot, no errors at starting kde. Yes, I am using nvidia drivers (that must be patched for realtime). Maybe with nuoveau or some other drivers...

I thank you all for your swift and knowledgeable replies. Aptosid features a great community. And what spock said about kudos to slh and all the devs goes for me as well. I had epic fails trying to get Debian Testing to work properly, but never any real problems with Aptosid.

For the moment, I'm trying to find out more about the performance of my setup as is. I'm using Qjackctl's status window for this. Apt-cache search latency came up with a tool called latencytop, but this seems to depend on special kernel configuration parameters, which I would have to do some research on first. Do you people have any other suggestions regarding diagnostics?

If all goes well, I'll increase the difficulty by adding ardour to the mix. And if that leads to a performance disaster, I may take you up on your kind offer, blackhole...

Hello,
Can someone please point me in the right direction as to get and install a realtime kernel. I need to run an application called Pianoteq, which is connected to the electronic keyboard through JACK and ALSA. I'm using ubuntu studio 11.04 and have horrible latency and crackling. Your help is appreciated.